'76 Fuel Guage Refusues to Work

[Knightpilot]

I've posted this on Broncofix.Com. I'm new here and thought I would try posting it here as well: Here's the summary so far: I have electricity going to the guage and leaving the guage. I've tested the guage using 2 "D"' cell batteries and it read 1/2 full (perfect, so guage works). The juice (volts) then flows to the fuel selector switch and leaves the switch just fine. The juice makes it all the way to the plug that goes into the fuel sensing unit. I cleaned the contacts for the unit and sprayed some contact fluid on it for good measure. Next, I put a wire brush on my drill and brushed the ground wire and everything associated with the ground wire. Next I measured the ohms across the sending unit and it read 10 ohms (because the tank is full). I went and checked the guage and the damn thing still reads zero.

My only thought is that the voltage coming out of the IVR is not constant - it fluctuates between less than one volt to six volts (hanging out around the 1 volt range with an occasional spike up to 6 volts). Can this be the only remaining problem? I would think the voltage from the IVR would be fairly constant around 5-6 volts. I hate to beat this issue to death, but I just can't get this thing to work. Thanks for your input. John

_________________

76 Bronco, 302, Auto Complete Rebuild

 

[Bully Bob]

I'm reasonably certain it should be a constant voltage.

The book calls it out as a "constant voltage unit".

 

[TX '73]

Reads 0 on either tank with them both full? Just typing out loud but I'm sure you know you're guage selector and tank selector are jirating together? Sending units are okay?

 

[BroncoJoe19]

Did you consider that the guage may work and the sending unit may work but the wires between them may be broken?

 

[BroncoJoe19]

Take a look at the 3rd and 4th posts of this thread... see if it helps

http://broncozone.com/forums/index.php?sho...amp;#entry29198

 

[fordman]

My fuel gauge was always reading empty, I found that the float on the sending unit was bad . I also noticed my IVR voltage was erratic i think that was due to it being a mechanical regulator and I was checking it with a digital meter with no load on the circuit. Try checking your sending unit resistance (ohms) at different fuel levels to see if it changes .

 

[wilber]

I've posted this on Broncofix.Com. I'm new here and thought I would try posting it here as well: Here's the summary so far: I have electricity going to the guage and leaving the guage. I've tested the guage using 2 "D"' cell batteries and it read 1/2 full (perfect, so guage works). The juice (volts) then flows to the fuel selector switch and leaves the switch just fine. The juice makes it all the way to the plug that goes into the fuel sensing unit. I cleaned the contacts for the unit and sprayed some contact fluid on it for good measure. Next, I put a wire brush on my drill and brushed the ground wire and everything associated with the ground wire. Next I measured the ohms across the sending unit and it read 10 ohms (because the tank is full). I went and checked the guage and the damn thing still reads zero.
My only thought is that the voltage coming out of the IVR is not constant - it fluctuates between less than one volt to six volts (hanging out around the 1 volt range with an occasional spike up to 6 volts). Can this be the only remaining problem? I would think the voltage from the IVR would be fairly constant around 5-6 volts. I hate to beat this issue to death, but I just can't get this thing to work. Thanks for your input. John

_________________

76 Bronco, 302, Auto Complete Rebuild

disconnect wires on fuel gauge test with ohm meter. needs to be 13 ohms took me lots of patience to figure out

 

[wilber]

I've posted this on Broncofix.Com. I'm new here and thought I would try posting it here as well: Here's the summary so far: I have electricity going to the guage and leaving the guage. I've tested the guage using 2 "D"' cell batteries and it read 1/2 full (perfect, so guage works). The juice (volts) then flows to the fuel selector switch and leaves the switch just fine. The juice makes it all the way to the plug that goes into the fuel sensing unit. I cleaned the contacts for the unit and sprayed some contact fluid on it for good measure. Next, I put a wire brush on my drill and brushed the ground wire and everything associated with the ground wire. Next I measured the ohms across the sending unit and it read 10 ohms (because the tank is full). I went and checked the guage and the damn thing still reads zero.
My only thought is that the voltage coming out of the IVR is not constant - it fluctuates between less than one volt to six volts (hanging out around the 1 volt range with an occasional spike up to 6 volts). Can this be the only remaining problem? I would think the voltage from the IVR would be fairly constant around 5-6 volts. I hate to beat this issue to death, but I just can't get this thing to work. Thanks for your input. John

_________________

76 Bronco, 302, Auto Complete Rebuild

 

[wilber]

disconnect wires from fuel gauge and test ohms needs to be 13ohms, tooks lots of patience but mine finnaly works